(1) Field of the Invention
The present invention relates to joined articles between ceramic members and other members as well as to a process for producing such joined articles.
(2) Related Art Statement
A process for directly joining substrates made of aluminum nitride sintered bodies is known. For example, in JP-A 2-124778, aluminum nitride substrates are integrated to each other through diffusion joining by heating the substrates at 1800.degree. C. to 1900.degree. C. JP-A 8-13280 discloses a joined body of aluminum nitride sintered bodies having relatively high strength.
Further, a process for brazing a nitride ceramic member to another nitride ceramic member or a metallic member is known. For instance, JP-A 8-277171, discloses a joined article having high corrosion resistance against a halogen-based corrosive gas such as ClF.sub.3 or the like by joining aluminum nitride members with a brazing material composed mainly of aluminum, copper or nickel and containing an active metal such as titanium. This brazing material is difficult to be corroded with the halogen-based corrosive gas, and easily wets the surface of the aluminum nitride member.
However, a problem exists in some uses. For example, in a semi-conductor-producing apparatus for a high temperature use, the joining layer joining the ceramic member to the metallic member is exposed to atmospheres inside and outside a semiconductor-producing chamber at temperatures not lower than 500.degree. C. The atmosphere outside the chamber is open air or an inert gas, and that the inside chamber is medium or high degree vacuum, for example, into which a halogen-based corrosive gas or ozone is fed.
For example, since an aluminum-based brazing material has a high vapor pressure in a high temperature range of not less than 500.degree. C., it is difficult to use. Further, since a silver-based brazing material, for example, a silver-copper-titanium based alloy brazing material also has a high vapor pressure in such a high temperature range of not less than 500.degree. C., it is volatized under high vacuum, and is likely to be oxidized upon contacting the open air to shorten the service life of the brazing material.